Forgetting a swimsuit — or deciding to buy one once you’re here — is more complicated in Japan than it looks. Sizing runs differently than in the US or Europe, the styles lean heavily toward sun protection rather than minimal coverage, and store stock disappears earlier in the summer than you’d expect. Here’s how to shop for swimwear in Japan without wasting an afternoon in a fitting room that doesn’t have your size.
How Japanese Swimwear Sizing Works
Japanese swimwear is sized in letters — S, M, L, LL, and occasionally 3L or 4L — rather than the numeric sizing common in Western women’s clothing. The key thing to know is that these letters run smaller than you’d assume: a US size Medium often fits closer to a Japanese L or LL, and plus sizing beyond LL is genuinely hard to find outside of a handful of specialty retailers. Bikini tops and bottoms are also frequently sold as separates rather than matched sets, which is actually useful — you can mix a top in one size with a bottom in another, something many overseas brands don’t allow.
Try everything on before buying. Most stores with fitting rooms require you to use a disposable face/hygiene seal (a thin adhesive liner, sometimes free, sometimes ¥50–100) before trying on swimwear or underwear, for hygiene reasons — look for a small dispenser or basket near the fitting room curtain, or ask staff for one (“kao-ate, onegaishimasu”). Skipping this step and trying to put a swimsuit over your face isn’t allowed in most shops.
What You’ll Actually Find on the Racks
Japan’s beach and pool culture is far more sun-conscious than many visitors expect, and the swimwear reflects that. Expect to see a lot of rash guards (long- and short-sleeve), swim leggings, UV-cut cover skirts sold separately from bikini bottoms, and one-piece suits with built-in shorts or high necklines. Pure string bikinis exist but are a smaller share of the floor than in, say, a US department store. For men, board shorts and compression-style swim trunks with a mesh liner are standard; Speedo-style briefs are mostly sold for competitive swimming, not beach wear. If you’re heading to a public pool rather than the ocean, note that many Japanese pools require a swim cap and specifically prohibit board shorts or anything with exposed pockets/zippers — worth checking before you buy if a pool, not a beach, is your destination.
Budget and Mid-Range: Chain Stores Are Your Best Bet
For most travelers, the cheapest and easiest route is Japan’s big clothing chains, which stock swimwear seasonally alongside their regular lines:
- GU — Uniqlo’s sister brand, the cheapest reliable option, with swim shorts and rash guards typically ¥990–1,990. Limited size range at the top end.
- Uniqlo — slightly better fabric and fit than GU, with swim shorts and rash guards around ¥1,500–2,990. Stock and sizing vary by store; flagship branches in Ginza and Harajuku have the fullest range.
- Decathlon (Kasai in Tokyo, Kashiwanoha, and a few other suburban locations) — the best bet if you need larger sizes, with swimwear built for actual swimming (chlorine-resistant fabric, proper competitive cuts) from roughly ¥1,500–3,000.
- Shimamura — a nationwide budget chain with very cheap swimwear (often under ¥2,000), but limited English signage and a narrower size curve.
- Don Quijote — not a dedicated swimwear retailer, but most locations stock cheap, novelty-leaning swimsuits and beach gear (goggles, floats, beach balls) in summer, and many stores stay open until midnight or around the clock, which is handy if you’re shopping the night before a beach day.
If you’d rather browse curated, slightly more fashion-forward basics than the fast-fashion chains offer, Japan’s select shops are worth a look too — see our guide to Beams, United Arrows & Journal Standard’s select shop culture for where these stores cluster and what to expect price-wise (generally ¥5,000–12,000 for swimwear here).
Department Stores and Splurge Options
Department stores like Isetan Shinjuku and Takashimaya carry both domestic and imported swimwear brands on their fashion floors, typically open 10:00–20:00. Prices run considerably higher (¥8,000–30,000+), but you get proper fitting assistance, a wider range of cup sizes for bikini tops, and sometimes English-speaking staff on the fashion floor — ask at the information desk near the main entrance. This is the better route if you wear a bra size that’s hard to match off a rack, since most chain-store swimwear tops come in generic S/M/L rather than cup sizing.
Best Time to Shop, and Mistakes to Avoid
Swimwear starts appearing in stores around late March, hits full stock through Golden Week (late April–early May), and goes on markdown from mid-July onward as retailers clear floor space for autumn clothing — by late August, size runs are picked over and some styles are gone entirely. If your trip lands in July or August and swimming is a priority, shop in the first week you arrive rather than waiting.
The most common mistakes: assuming your home size translates directly (size down your expectations, or size up the garment); waiting until the week of your beach trip to shop, when LL and above sizes are often sold out; and not realizing cover-ups, rash guards, and UV leggings are sold as separate add-on pieces rather than included — budget an extra ¥1,500–3,000 if you want the full sun-protected look that’s standard on Japanese beaches.
Shopping Near the Beach Itself
If you’re heading somewhere coastal, it’s worth knowing how much (or little) swimwear shopping is available once you arrive. In Shimoda, the Izu Peninsula port town with some of the region’s best beaches, you’ll find small resort-wear boutiques near the beach road, though selection is limited compared to Tokyo — fine for a cover-up or a forgotten rash guard, not for finding your exact size. Further afield, on remote islands like Tokunoshima in Kagoshima, dedicated swimwear shops are essentially nonexistent, so buy before you fly out — the nearest real options are back on the mainland or in Amami Oshima’s larger towns. The general rule: buy in a city (Tokyo, Osaka, Naha) before you head to the smaller, quieter coastline, not after.
However you end up shopping, trying things on is non-negotiable here — Japanese swimwear’s smaller size curve and sun-protective extras mean a suit that looks right on the rack can fit very differently than what you’re used to at home.